Source : Webster's Revised Unabridged Dictionary (1913)

Inextirpable \In`ex*tir"pa*ble\, a. [L. inexstirpabilis: cf. F.
   inextirpable. See {In-} not, and {Extirpate}.]
   Not capable of being extirpated or rooted out; ineradicable.

Source : WordNet®

inextirpable
     adj : incapable of extermination or extirpation; "some weeds seem
           inextirpable" [syn: {inexterminable}]